Opals are described according to their transparency and body color. Opals with a vivid play-of-color and a black or other dark body color are called black opals. Top-quality black opals are highly prized and were discovered in the legendary Lightning Ridge opal field in Australia in 1903. Opals are typically cut as cabochons or polished free-form to best show the play-of-color. The Dark Jubilee Opal pictured here is a 318.4-carat free-form polished black opal from a mine in Coober Pedy, Australia, another famous region known for black opals. Coober Pedy means "a man in a hole" in a regional aboriginal language, and many miners do live in the underground excavations there. The Dark Jubilee Opal was a gift of the Zale Corporation in 1980.